Apparatus for maintaining uniform pressure.



No. 858,088. PATENTED JUNE 25, 1907.-

' W. B. MASON.

APPARATUS FOR MAINTAINING UNIFORM PRESSURE.

APPLICATION FILED MAY 16. 1906.

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W. B. MASON.

APPARATUS FOR MAINTAINING UNIFORM PRESSURE.

APPLIOATION FILED MAY 18. 1906.

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IINITED STATES PATENT OFFICE.

WILLIAM B. MASON, OF BOSTON, MASsAoHUSETTS, ASSIGNORTO THE MASONREGULATOR COMPANY, OF SACO, MAINE, A CORPORATION OF MAINE.

APPARATUS FOR MAINTAINING UNIFORM PRESSURE.

Specification of Letters Patent.

Patented June 25, 1907.

Application filed May 16, 1906. Serial No- 317,106.

' of which the following is a specification, reference being had thereinto the accompanying drawings.

It is fre uently the case that driers and other simi ar devices arerequired to be heated at a constant pressure by steam from a source ofsteam supply which is itself variable in pressure, as, for instance, theexhaust steam from an engine.

My invention is applicable to any chamber which is heated from avariable source of steam supply, and in which it is desired to maintainuniform pressure. In the case of a paper drier, which is heated by theexhaust steam from an engine, and in which it is desired to maintain auniform pressure of perhaps five pounds by means of steam from anexhaust pipe which ordinarily has a pressure of six or seven pounds, itwill be found that it is necessary to vent the exhaust pipe or thechamber to the atmosphere to permit the escape of a sufficient portionof the steam from the exhaust to prevent the pressure in the drier orchamber rising above the predetermined point. On the other hand, it willalso probably be found that on certain occasions the pressure in theexhaust pipe will fall below the predetermined pressure for the drier orchamber, and that consequently it is desirable that steam at a greaterpressure be introduced into the said drier or chamber to raise thepressure to the predetermined point. This is best accomplished byintroducing live steam into the chamber directly from the boiler.

My invention has for its object a device or system for controllingautomatically the venting of the steam from the chamber when thepressure rises too high and the admission of the steam to the chamberwhen the pressure falls too low.

The invention affords a simple mechanism which is controlled by thepressure in the chamber and which maintains the said pressure atsubstantially the predetermined point by means of the occasionaloperation of the valves controlling the-vent to the atmosphere and theinlet of steam from the boiler.

I believe my invention to be a broad one and to be susceptible of beingembodied in a considerable variety of forms.

For convenience I havedescribed the invention in connection with thesupply of steam to a number of chambers where the amount of steamrequired is large, and accordingly where the steam pipes and variousvalves are of large size, so that it is inconvenient or impossible tocarry the pipes to a board or panel, it being necessary that the valvesbe located at points determined by the locations of the steam pipes.This is one form in which I put the invention into actual operation, butI desire not to be limited to this form as my invention is a broad oneand capable of a variety of applications and embodiinents.

The invention will be fully understood from the following specificationtaken in con nection with the accompanying drawings, and the novelfeatures thereof are pointed out and clearly defined in the claims atthe close of the specification.

Referring to the drawings,-Figure 1 is a diagrammatic view of the deviceembodying my invention. Fig. 2 is a section of the fluid pressureactuated device which Operates the valves. Fig. 3 is a vertical sectionshowing the interior construction of the high pressure valve.

Referring now to the drawings, and particularly to Fig. 1, at A isindicated the ex haust pipe of an engine which supplies steam throughvarious connections to chambers or driers not shown, to each of whichleads one of the small pipes B.

At 0 is shown the vent to the atmosphere cont-rolled by the vent valve Das will be later described. This valve D is opened at various times whenthe pressure in the chamber rises above the predetermined point. Whenthe pressure in the chambers falls below said predeterminedpoint, steamfrom a boiler, not shown, is admitted through the live steam pipe E andthe admission of this steam. is controlled by the high pressure valve F.

The interior construction of the vent valve D and the high pressurevalve F is illustrated in Fig. 3, which shows the interior of the highpressure valve F in section. The two valves D and F are exactly alike inconstruction except for the arrangement of their valve levers. The valveF is operated by means of a lever 10 pivoted at 11 to a movable fulcrum12 which is itself pivoted at 13 to a fixed portion of the frame orcasing of the valve. The valve lever 10 is pivoted to the valve spindle14 at 15, and its end extends beyond the said point of connection withthe said valve spindle 14 and enters a slot 16 (see Fig. 1) in an arm 17which is fixed to and extends upwardly from the frame or casing of thevalve. This arrangement serves to guide the valve lever. The valve isopened by the downward movement of the right hand end of the lever 10.

In the case of the vent valve D, the posi tions of the parts arereversed so that the valve is closed by the downward movement of itslever arm 18. In the valve D the lever arm 18 is pivoted at 19 to thevalve spindle 20, and at 21 to the movable fulcrum 22 which in this caseis on the opposite side of the valve spindle so that the action of thevalve lever is reversed. The valve lever 18 is also guided in the slot23 in the upwardly extending arm 24, which is fixed to the frame orcasing of the valve. These valves are preferably balanced piston valvesas seen in Fig. 3 where the two valve seats are desig nated 25 and 26.Both the u per valve 27 and the lower member 28 are slightly beveled sothat the valve opens gradually.

The pressure weighing device now to be described is of any suitablecharacter and is movable in response to changes in ressure in the dryingchamber. Such a evice is shown and described in my Patent No. 561,600,dated June 9, 1896 for a damper regulator. In the following description,I have accordingly thought it necessary to describe the operation ofthis device only generally and further reference may be had, if desired,to the above mentioned Letters Patent. This pressure weighing device G,which is shown in perspective at the right of Fig. 1 and in section inFig. 2, operates the vent valve D and the high pressure valve F in thefollowing manner. The pressure weighing device G is connected by a pipeH of suitable size with the chamber in which it is desired to maintainuniform pressure or with the pipe leading thereto as is shown in Fig. 1.The pipe H leads to the diaphragm chamber 29 and the pressure in thesaid chamber 29, when it rises above or falls below the predeterminedoint, moves the lever arm 30 upon which is ocated the adjustable weight31 which may be moved to vary the predetermined pressure to bemaintained in the drier or chamber.

When the ressure in the chamber falls below the prec etermined point,that is, when the exhaust pipe A from the engine is not furnishingsufiicient steam or steam at too pressure supplied from the city mainsor other suitable source to be exhausted from the upper side of thepiston 36 as explained in my previous patent above referred to. When thepiston 36 rises, it permits the chain 45, which is wound up on the rimof a wheel 44; on the outside of the pressure weighing device G, to beunwound.

. The chain 15 is connected to the valve levers 10 and 18 in thefollowing manner. It

passes first over the two sheaves 46 and 47, then about the sheave 48,which is supported in afork or link 49 on the end of the valve lever 10.From there, it passes over a second pair of sheaves 50 and 51, aboutanother sheave 52 similarly mounted on the end of the valve lever 18,and thence to some fixed. point, as the hook 53. The valve lever 10 isprovided with the light Weight 54 near the fulcrum 12 while the valvelever 18 is provided with a heavier weight 55 at a greater distance fromits fulcrum 22. The high pressure valve F is, therefore, operated moreeasily than the vent valve D. When the exhaust of Water from the upperside of the piston 36 slackens the chain 15, it will be seen that thevalve lever 18 which. operates the vent valve D drops first because itsweight is the heaviest, thus closing the vent valve. When the vent valveis closed by this action, the chamber or drier will receive steam at thefull pressure of the exhaust. If this is greater than the predeterminedpressure, the vent valve will again be opened by the reverse operationof the pressure weighing device to bring the pressure in the chamberdown to the predetermined point. If, on the contrary, the full flow ofexhaust to the chamber is insufficient to keep the pressure up to thepredetermined point, then the vent valve will remain closed, and thecontinued rise of the iston 36 in the pressure weighing device wilpermit the valve lever 10 of the high pressure valve F to sink, therebyopening said high pressure valve F and admitting sufficient steam to thechamber to bring the pressure up to the predetermined point.

When the pressure in the chamber has risen above the predeterminedressure by reason of the opening of the high pressure valve F, thereverse action takes place. The increased pressure in the diaphragmchamber 29 causes the lever 30 to rise and admits water under pressureto the upper side of the piston 36, thus causing the said piston todescend and to wind the chain 45 on the outside wheel 44. As the chain45 is shortened, it causes the valve F to close first, as that valve isless heavily weighted. If shutting off the flow of live steam wholly orpartly by means of the closing of the high pressure valve is notsuflicient to cause the pressure in the chamber to fall to thepredetermined point, the continued shortening of the chain 45 by thecontinued downward movement of the piston 36 lifts the vent valve lever18 and o ens that galve, thus reducing the pressure in t e cham- Inactual practice, I find that the amount of steam flowing from theexhaust pipe A is usually more than suflicient to maintain the desiredpressure in the chamber. As long as this is the case, the high pressurevalve lever 10 will be held in its upper position and the valve keptclosed so that the sheave 48 011 the valve lever 10 will then form forthe time being a fixed abutment, and the pressure of the steam in thechamber will be controlled entirely by the vent valve which will openslightly to reduce the pressure and close again to increase it. When,however, the steam from the exhaust pipe A is insuflicient to maintainthe desired pressure, the high pressure valve will come nto operationand thus the predetermined pressure will be maintained in the chamberunder all conditions of the exhaust.

Of course, it is to be understood that any variable source of supply maybe employed and any high pressure source of supply may be used to draw uon when additional pressure is required. t is also obvious that theapparatus is equally applicable to all kinds of fluid pressures whichrequire to be used under the conditions herein described.

I claim as my invention:

1. Controlling mechanism for maintaining a constant predeterminedpressure in a cham bcr which is connected with two sources of supply,one source being normally of low variable pressure, and the other ofhigh pressure, which comprises a vent valve and a high pressure valve,and operating means for the said valves comprising a pressure weighingdevice connected with said chamber and movable in response to changes'inpressure therein, and operating to open or to close the said vent valveor the said high pressure valve as may be required to maintain thepredetermined pressure in the chamber.

2. Controlling mechanism for maintaining a constant predeterminedpressure in a chamber which is connected with two sources of supply, onesource being normally of low variable pressure, and the other of highpressure, which comprises a vent valve and a high presmined point and toclose the high pressure v valve and open the vent valve -when thepressure in the chamber rises above the said predetermined point.

3. Controlling mechanism for maintaining a constant predeterminedpressure in a chamber supplied with fluid pressure from two sources ofsupply, one of which is variable and the other of which is of relativelyhigh pressure, which comprises a vent valve, an operating levertherefor, a high pressure valve, an operating lever therefor, weights onthe said valve levers, the weight on the said vent valve being mosteffective, and operating means for said valves comprising a pressureweighing device connected with the said chambers andmovable in responseto changes 1n pressure therein, and flexible connectlng means betweenthe said operating means and the said valve levers and operating uponthe said less effectively weighted lever arm first as the pressure risesand upon the more pflirlectively weighted lever first as the pressure 4.Controlling mechanism for maintaining a constant predetermined pressurein a chamber supplied with fluid pressure from two sources of supply,one of which is variable and the other of which is of relatively highpressure, a vent valve provided with a valve lever fulcrumed to open thesaid valve as the long arm of the lever rises, a high pressure valveprovided with a valve lever fulcrumed to close the said valve as thelong arm of the said valve lever rises, weightson the said valve levers,the weight on the said vent valve being most effective, and operatingmeans for said valves comprising a pressure weighing device connectedwith the said chambers and movable in response to changes in pressuretherein, and flexible connecting means between the said operating meansand the said valve levers and operating upon the said less effectivelyweighted lever arm first to close the high pressure valve and open thevent valve when the pressure in the chamber rises above thepredetermined point, and to close the vent valve and open the highpressure valve when the pressure in the chamber falls below thepredetermined point.

In testimony whereof I aflix my signature, in presence of two witnesses.

WILLIAM B. MASON. Witnesses:

GEORGE P. DIKE, J. HENRY PARKER.

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